The Assessment of Specimens Procured by Endoscopic Ampullectomy

Andrew M. Bellizzi, MD; Michel Kahaleh, MD; Edward B. Stelow, MD

Disclosures

Am J Clin Pathol. 2009;132(4):506-513. 

In This Article

Abstract and Introduction

Abstract

Endoscopic ampullectomy (EA) is increasingly used in the management of ampullary neoplasia. Although studies on the safety and efficacy of this procedure exist, no study has specifically addressed the histopathologic features of the specimens. We review our experience with 45 EA specimens assessed for the following: diagnosis, high-grade dysplasia (HGD), submucosal ampullary gland/ductule involvement, specimen integrity, and margin status. Familial adenomatous polyposis (FAP) status and the endoscopist's impression of completeness of removal were also ascertained. Previous biopsy diagnoses were compared with ampullectomy diagnoses, and histologic and clinical features were correlated with disease persistence. The histologic features of the ampullectomy specimens were as follows: diagnosis (no diagnostic abnormality, 3; reactive, 8; adenoma, 26; adenocarcinoma, 7; other, 1); HGD, 1; submucosal ampullary gland/ductule involvement, 20; specimen integrity (intact, 22; fragmented, 23); and margin status (positive, 20; negative, 2; could not be assessed, 12). Five patients had FAP, and EA was deemed complete in 21 (47%). The diagnostic agreement between preampullectomy biopsy and ampullectomy was 64%. Of the patients, 33 (73%) had documented persistent disease. None of the histologic or clinical features had a statistically significant relationship with disease persistence.

Introduction

The ampulla of Vater is a complex anatomic structure composed of the distal-most, intraduodenal portions of the common bile duct and pancreatic duct, which usually join to form a common channel. These ducts are lined by pancreato-biliary-type epithelium. Viewed from the duodenal lumen, this structure projects as the duodenal papilla and is covered by small intestinal–type epithelium.[1]

The ampulla is recognized as a preferred site for development of duodenal epithelial neoplasia. In patients with familial adenomatous polyposis (FAP), the incidence of ampullary adenoma has been shown to approximately equal that for the remaining duodenum.[2] This is believed to reflect the anatomic complexity and function of the region; it is an epithelial transition zone bathed in pancreatic juice and bile.[3]

A variety of therapeutic options exist for the management of ampullary neoplasia. Pancreatoduodenectomy is considered the "gold standard." It is still the first choice for the treatment of most ampullary adenocarcinomas and, at many centers, for the management of large ampullary adenomas.[4] There has been a drive toward less invasive procedures, with the goal of minimizing morbidity and mortality. Transduodenal ampullectomy is an open surgical procedure that involves removal of the duodenal papilla with reimplantation of the distal common bile duct and pancreatic duct into the wall of the duodenum. This procedure is used at some centers in the management of large adenomas and a select population of low-stage, low-grade ampullary adenocarcinomas.[5,6]

Endoscopic ampullectomy (EA; also referred to as endoscopic papillectomy or endoscopic snare resection) obviates the need for laparotomy. Given technological advances and greater access to interventional endoscopy, this technique has been increasingly used in the last decade in the management of ampullary adenomas. There are also scattered case reports of its use in small ampullary adenocarcinomas and neuroendocrine neoplasms.[7,8] (Often in these reports EA represents a "minimally invasive" alternative in patients deemed "poor surgical candidates.")

The endoscopist visualizes the papilla (and the attendant adenoma) with a side-viewing endoscope. Cholangiography and pancreatography are performed to assess for proximal extension of the lesion. Papillotomy can allow for access to intra-ampullary lesions. Saline or dilute epinephrine can be injected into the submucosa deep to the lesion, lifting the lesion and facilitating snare resection. Residual lesional tissue can be removed piecemeal with forceps or thermally ablated, typically with argon plasma coagulation. Finally, stents can be placed for ductal decompression.[9–11]

The goals of this study were several-fold. Fundamentally, we sought to describe the histologic features of specimens obtained by EA. Endoscopic biopsy of the ampulla has been criticized as inaccurate, with reported diagnostic accuracies ranging from 62% to 85%.[6,12–14] We explored this issue through the comparison of preampullectomy and ampullectomy diagnoses. We also have histologic follow-up for the majority of our cases, permitting a glimpse of what pathologists might expect to see in biopsy specimens following ampullectomy and allowing comment on the therapeutic usefulness of EA.

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